This invention relates to a process of producing or recovering energy, particularly of producing electric energy, by the utilization of the pressure and heat potentials of exhaust gases formed in chemical syntheses, particularly in the synthesis of methanol.
Many chemical reactions result in exhaust gases, which cannot be utilized further or which would have to be purified at high expense before their further utilization. These exhaust gases often contain sensible heat, which is lost, as a rule.
It has already been proposed to recover heat in chemical processes, e.g., in the synthesis of methanol.
German Pat. No. 2,013,297 describes a process in which the reaction heat is utilized which is generated when methanol is produced from a synthesis gas which contains carbon oxides and hydrogen and which has been produced by a cracking of hydrocarbons by a treatment with water vapor on an indirectly heated, nickel-containing catalyst at temperatures above 700.degree. C, and which synthesis gas is reacted on a copper-containing catalyst under pressures of 30-80 kg/cm.sup.2 and at temperatures of 230.degree.-280.degree. C. The latter catalyst is contained in tubes which are indirectly cooled with water with production of high-pressure steam. The resulting high-pressure steam can be expanded to a back-pressure of 4-6 kg/cm.sup.2 with performance of work, and the remaining low-pressure steam may be used to supply heat to the final distillation of the methanol which has been produced.
Some syntheses involve a formation of exhaust gases which contain not only sensible heat but are under the pressure under which the synthesis has been effected. This pressure may amount, e.g., in the synthesis of methanol, to 200 bars (German Pat. No. 1,668,390) and has not yet been utilized for a production of energy.